import React, { Component } from 'react'
// 引入store 用于获取redux中的状态
import store from '../../redux/store.js'

export default class Count extends Component {
  state = {}
  // componentDidMount() {
  //   // 检测redux中状态的变化,只要变化,就调用render
  //   store.subscribe(() => {
  //     this.setState({})
  //   })
  // }
  // 加法
  increment = () => {
      const {value} = this.selectNumber;
      // 通知redux加value
      store.dispatch({type:'increment', data: Number(value)})
  }
  decrement = () => {
    const {value} = this.selectNumber;
    store.dispatch({type:'decrement', data: Number(value)})
  }
  // 奇数再加
  incrementIfOdd = () => {
    const {value} = this.selectNumber;
    const count = store.getState();
    if(count % 2 !== 0) {
      store.dispatch({type:'increment', data: Number(value)})
    }
  }
  incrementAsync = () => {
    const {value} = this.selectNumber;
    setTimeout(() => {
      store.dispatch({type:'increment', data: Number(value)})
    }, 500);
  }
  render() {
    return (
      <>
        <h1>当前求和为: {store.getState()}</h1>
        <select ref={(c) => (this.selectNumber = c)}>
          <option value="1">1</option>
          <option value="2">2</option>
          <option value="3">3</option>
        </select>
        &nbsp;
        <button onClick={this.increment}>+</button>&nbsp;
        <button onClick={this.decrement}>-</button>&nbsp;
        <button onClick={this.incrementIfOdd}>当前求和为奇数再加</button>&nbsp;
        <button onClick={this.incrementAsync}>异步加</button>&nbsp;
      </>
    )
  }
}
